Incinerator stoker siftings conveyor mechanism

ABSTRACT

An incinerator having a plurality of air plenums respectively disposed beneath successive sections of a stoker grate system, each plenum being hermetically sealed off from one another for independent delivery of air for combustion under any desired positive pressure for burning trash deposited on the grate system. The plenums serve also as hoppers through which the grate siftings are discharged into an underlying conduit filled with water within which is accommodated an endless drag chain conveyor mechanism having a lower run of flights which moves along the bottom of the conduit for transfer of the siftings deposited therein to a discharge station and an upper run of flights which move in an undulating path in the region of the water surface to skim off from the water surface floating particles of the burnt material and force them to be submerged in the water for gravity fall thereof to the bottom run of the conveyor mechanism.

United States Patent Hampton INCINERATOR STOKER SIFTINGS CONVEYOR MECHANISM [76] Inventor: Robert K. Hampton, 119 Somerset Ave., Garden City, N.Y.

[22] Filed: July 31, 1972 [21] Appl. No.: 276,859

[52] U.S. Cl 110/8 R, 110/165, 110/171 [51] Int. Cl. F23g 5/00 [58] Field of Search 110/8 R, 40 R, 165 R, 110/171 [56] References Cited UNITED STATES PATENTS 2,589,836 3/1952 Martin 110/165 3,031,981 5/1962 Smauder 110/165 X 3,133,804 5/1964 Hardgrove 110/165 X 3,504,645 4/1970 Davenport 110/8 Primary Examinerl(enneth W. Sprague Att0rneyLeon Edelson et a1.

[ ABSTRACT An incinerator having a plurality of air plenums respectively disposed beneath successive sections of a stoker grate system, each plenum being hermetically sealed off from one another for independent delivery of air for combustion under any desired positive pressure for burning trash deposited on the grate system. The plenums serve also as hoppers through which the grate siftings are discharged into an underlying conduit filled with water within which is accommodated an endless drag chain conveyor mechanism having a lower run of flights which moves along the bottom of the conduit for transfer of the siftings deposited therein to a discharge station and an upper run of flights which move in an undulating path in the region of the water surface to skim off from the water surface floating particles of the burnt material and force them to be submerged in the water for gravity fall thereof to the bottom run of the conveyor mechanism.

8 Claims, 6 Drawing Figures INCINERATOR STOKER SIFTINGS CONVEYOR MECHANISM This invention relates generally to incinerators and more particularly to an incinerator system for the collection and disposition of siftings as the products of combustion of trash burnt upon the stoker grates of the incinerator.

Among the principal objects of the present invention is the provision of means in an incinerator of collecting the burnt refuse sifting down through the grate system of the incinerator in a water-filled conduit disposed beneath and extending length-wise of the grate system and effecting their discharge by a continuously operating conveyor mechanism enclosed in said housing.

An important object is to provide in the incinerator a plurality of plenums each adapted to individually supply air for combustion under a predetermined positive pressure to each of a plurality of successive sections of the incinerator stoker or grate system, which plenums serve as hoppers for receiving and discharging the siftings from the stoker grates into the above mentioned water-filled conveyor housing for eventual discharge therefrom by the conveyor.

A further important object is to insure that the several air plenums are effectively sealed from one another so that each may provide its own supply of air for combustion to the section of the grate system operating under control of a given air plenum, thereby insuring that any untoward change in the pressure of air in a particular plenum will not affect or change the desired operating air pressure of any other plenum.

A still further and important object of the invention is to provide means for effectively causing light particles of the burnt trash which sift through the grate system and are discharged by way of the air plenums into the water-f1lled conveyor housing to be pulled into the water and so cause the same to be wetted and drop of their own weight to the bottom of the conveyor housing from whence they are dragged out by the conveyor it self.

A more specific object of the invention is to provide a conveyor mechanism of the endless drag chain type having upper and lower continuously moving runs of flights with means for causing the upper run to traverse an undulating path of travel along the surface of a body of water contained in a housing for the conveyor mechanism so that, as said conveyor moves in said water, the upper run of flights is submerged at spaced points along their line of travel and carry with them into the water the burnt products of combustion floating on the water surface.

The foregoing and other objects of the present invention will appear more fully from the following description, it being understood that the invention consists substantially in the combination, construction, location and relative arrangement of parts as hereinafter described, as shown in the accompanying drawings and as finally pointed out in the appended claims.

In the accompanying drawings: I

FIG. 1 is a longitudinal sectional view of the stoker portion of an incinerator having incorporated therein the siftings conveyor mechanism constructed in accordance with the principles of the present invention;

FIG. 2 is a transverse sectional view as taken along the line 2-2 of FIG. 1;

FIG. 3 is a longitudinal sectional view of a portion of the siftings conveyor mechanism as taken along the line 3-3 of FIG. 2;

FIG. 4 is a perspective view of a portion of the conveyor mechanism housing showing one of the several air baffles or stops which are respectively associated with the siftings discharge chutes of the incinerator in accordance with the principles and objectives of the present invention;

FIG. 5 is an enlarged longitudinal sectional view of the frontal portion of the enclosed conveyor mecha nism; and

FIG. 6 is a correspondingly enlarged longitudinal sectional view of the rear of head end portion of the enclosed conveyor mechanism.

Referring now more particularly to the drawings, it will be observed that the incinerator generally designated A, which may be of any conventional type and construction, is provided with a feed chute 8 for the trash to be burnt in communication with a combustion chamber 9 within which are disposed a plurality of stoker grates 10 arranged in longitudinally spaced stepped relation. These grates, which may be vibrated by any suitable grate vibrating means (not shown), operate to feed the trash to be burned in the incinerator downwardly along the inclined plane of the grates under the influence of gravity for eventual discharge through a discharge chute 11 at the lower rear end of the grate system into a trash collecting truck 12 or other device for moving the unburned residue away from the incinerator.

Each grate tops off a separate plenum or chamber 13 through each of which air for combustion is delivered under positive pressure upwardly to and through the grates which plenums serve also as chutes for receiving and discharging therethrough that portion of the trash which is burnt on the grate and is disintegrated sufficiently to pass therethrough as siftings.

Any suitable means may be employed for firing the stokers, as, for example, gas or oil-fired burners (not shown) which may be common to all of the stokers or individually associated with each stoker. Each plenum is individually provided with its own supply of air under a pre-determined positive pressure for delivery to and through the grate overlying the top of each plenum. Thus, any suitable blower system may be employed for for delivery of air for combustion to each of the individual plenums, it being important only that the plenums be sealed from one another so that there is no air flow from one plenum to another, thereby insuring that each plenum is furnished with its own supply of air at a positive pressure predetermined for most efficient combustion of the trash upon the stoker grate immediately associated therewith. Preferably, such air for combustion is introduced into the plenum through suitable inlets or ports provided in the plenum discharge conduits preferably in the portions thereof which extend below the floor 15 of the combustion chamber.

It will be understood, of course, that the number of grates and combustion plenums may be varied as desired, as the overall size and length of the incinerator may require.

These plenums or chambers 13 are each provided with a discharge conduit 14 which extends downwardly through the floor 15 of the incinerator combustion chamber into the top wall of a longitudinally extending housing 16 for enclosing an endless drag chain type conveyor designed generally by the reference numeral 17. This housing 16, which is spaced below the floor of the combustion chamber as best shown in FIG. 1, has it top wall sealed about the perimeter of each conduit 14 to prevent influx of air into its associated plenum except by way of the air inlet located above the top of the conveyor housing. The drag chain conveyor enclosed in the housing 16 is of conventional type having a pair of laterally spaced sprocket chains 1818 (see FIG. 2) which carry therebetween a plurality of transversely extending parallel flights or scrapers 19 spaced uniformly along the lengths of the chains.

The drag chain conveyor 17 is fully contained within the housing 16 and, as most clearly appears in FIG. 1, the flights 19 thereof along the lower run of the conveyor drag along the bottom of the housing which may, if desired, be provided with a replaceable bottom liner to serve as a wear plate for the drag flights of the chain. The rear end of the housing 16 is upwardly inclined toward a discharge chute 20 supplementing the discharge chute 11 for delivering the siftings dragged out of the housing by the chain conveyor. Suitably fitted in this upwardly inclined rear end of the chain housing just above the discharge chute 20 are a pair of head sprockets 2l2l about which are entrained the opposite side chains 18l8 of the conveyor. These head sprockets 2121 are operatively connected to a common shaft 22 which is suitably driven by a motor 23 through a chain and sprocket drive 24.

The sprocket chains l8-18 of the chain conveyor at its extreme forward end are trained over vertically spaced pairs of sprockets 25 and 26 and an auxiliary pair of guide sprockets 27, all suitably journalled in a vertical extension 28 of the housing.

The conveyor housing 16 is filled with water supplied from any suitable source, the water level being maintained by any suitable means (not shown) at a level sufflciently spaced below the top of the housing to completely submerge the lower run and partially submerge the upper run of the drag chain conveyor in the water. This water level is indicated in FIGS. and 6 by the heavy dashed lines therein designed by the reference numeral 29, it being noted that the water level 29 is at all times maintained sufficiently below the bottom open ends of the plenum discharge conduits 14 as to permit the siftings of the trash burned on the grates to drop freely into the water contained in the conveyor housmg.

Provided in the conveyor housing 16 in immediate association respectively with the discharge conduits 14 of the several plenums are a series of baffle members 30 each of which serves a two-fold function, namely, first, to seal off the air plenums one from another as hereinbefore mentioned, and, second, to cause the upper run of the conveyor drag chain to continuously dip into and be completely submerged in the water in the conveyor housing at spaced points along its length beneath the siftings discharge conduits 14 to thereby effectively submerge any siftings which lodge upon said upper run of the chain conveyor for discharge of the siftings to and upon the floor of the conveyor housing.

These baffles or air seal 30 are each of the general design and construction best shown in FIG. 4 wherein it will be observed that each of said baffles is in the form ofa downwardly curved plate having its rear edge 32 welded or otherwise integrally secured to the top wall 33 of the conveyor housing 16 with its parallel front edge disposed substantially above the water level 29. The opposite side edges 34-34 are similarly secured to the opposite side walls 3535 of the housing. It will be noted that the curvature of the baffle 30 is such that when the same is secured in place as described, its curved bottom 36 is submerged below the level 29 of the water contained in the conveyor housing. Since all four edges of the baffle are so disposed relatively to the housing as to provide an 'air-tight seal between the jointed baffle edges and the housing, it will be apparent that the downwardly curved bulge of the baffle, when submerged in the housing-contained water with the front edge of the baffle disposed above the water level will provide an air seal or stop along the full width of the baffle in the region of its submergence in the water.

As most clearly appears in FIG. 1, these air stops or baffles 30 are spaced longitudinally along the length of the conveyor housing in such relation to the several plenums 13 as to seal off any possibility of air for combustion flowing from one plenum to another by way of the air space above the level of water in the conveyor housing, thereby insuring that each plenum is furnished with its own adequate supply of air for combustion under a predetermined positive pressure. Also, the air stops or baffles 30 preclude any possibility of back pressure developing in any one plenum from adversely affecting the operating air pressure in another plenum. To this end, the air baffles 30 are each preferably located at a point just in advance of the plenum with which it is associated, one such plenum being thereby disposed between each successive pair of the plenums, as well as between the front most plenum and the front wall of the conveyor housing.

While the bafi'les 30 may each be located at any suitable point spaced in advance of each plenum in order to operate effectively as air seals between the plenums as above described, it is preferable to locate each such baffle at a point closely adjacent the front of each plenum as shown in the drawings so that it may serve as a deflector to cause the upper run of chain conveyor to transverse an undulating path beneath the open bottom ends of the several discharge conduits 14. As the siftings from the stoker grates are dropped upon the upper run of the chain conveyor, they are effectively submerged in the water by the undulating travel of the conveyor upper run and are washed from and/or shaken off of said run for eventual deposit on the bottom' of the conveyor housing from whence they are dragged out of the housing by the bottom run of the chain conveyor.

Also, the baffles 30, acting as deflectors to force the drag flights of the upper run of conveyor down substantially below the water level in the conveyor housing, cause the siftings and burnt debris discharged downwardly through the stoker grates to become waterlogged sufficiently to effect their rapid sinking through the water to the bottom of the conveyor housing. This chain-deflecting action of the baffles is particularly effective in respect to siftings and other particles of the trash burned on the stoker grate which are of such low specific gravity as to cause them to float upon the water in the conveyor housing. The flights of the upper run of the chain conveyor, moving between the deflectors 30 in the direction indicated by the arrow in FIG. 1, skim these floating particles along the water level to the regions where these flights are submerged under the water level and thereby wet down the floating particles sufficiently to cause them to descend of their own weight through the water for engagement thereof by the drag-out flights of the lower run of the conveyor.

The upwardly inclined rear end of the conveyor housing is designed to provide for corresponding upward inclination of the discharge end of the chain conveyor so that as the siftings are dragged onto this inclined section of the conveyor above the water level they are substantially de-watered just prior to their discharge from the conveyor.

In the operation of the incinerator, the major portion of the trash resting upon the stoker grates l0 burns and disintegrates sufficiently to cause the residue to pass through the grates to be finally dropped into the water contained in the conveyor housing, while the larger non-combustible particles of the trash are carried by the grates to the rear end of the grate system from whence they are discharged by way of the aft discharge chute 11. The grate siftings which fall into the conveyor housing by way of the several plenums l3 eventually settle down in the water and are dragged out in their substantially de-watered condition, as thereinbefore described, by the working bottom run of the chain conveyor moving in the direction indicated by the arrow in FIG. 1 for eventual discharge from the conveyor by way of its chute 20 into a trash collecting truck 12 or other device. As shown in FIG. 1, the chain conveyor discharge chute 20 may be combined with the discharge 1 l at the rear end of the grate system so that the unbumt trash and residue passing off of the grate system and the siftings dragged out of the watercontaining conveyor housing may be simultaneously discharged, under control of a discharge gate 37, into the trash disposal or collecting unit.

It will be understood, of course, that any suitable type of mechanism may be employed to convey the siftings deposited in the water-filled housing to their point of discharge and that in lieu of employing a single conveyor as illustrated running under all of the spaced plenums, separate conveyors may be utilized for each plenum section of the incinerator in such manner that each conveyor effects transfer of the siftings collected by it onto its next succeeding conveyor for eventual discharge of the sifting by the last section of the conveyor system. Also, in addition to the air baffles as shown, other suitable means, such as guide rollers and the like, may be provided in the conveyor housing spaced lengthwise along the upper run of the conveyor to depress said run at spaced intervals and so cause the upper run to move along an undulating path for effecting submergence in the water of particles which may tend to float upon the water surface and thereby wet them down sufficiently so that they will sink to the bottom of the conveyor housing.

It will be understood that various other changes and modifications of the present invention may be made from time to time without departing from the general principles or the real spirit thereof, and it is accordingly intended to claim the same broadly, as well as specifically as indicated in the appended claims.

What is claimed as new and useful is:

1. In an incinerator having a combustion chamber and a grate system therein for moving trash to be incinerated longitudinally from the front to the rear end thereof through said combustion chamber, in combination, a water-retaining trough extending lengthwise of and spaced vertically below said grate system, said trough having enclosing top, bottom and side walls and being filled with water to a substantially constant level spaced from the top wall of the trough, a plurality of open-ended plenums disposed in tandem relation lengthwise of said grate system with their top ends respectively immediately underlying successive sections of said grate system and their bottom ends respectively projecting through the top wall of said trough to points spaced above the level of the water therein, and baffle means secured to the top wall of said water trough and projecting into the water to block the passage of air from one plenum to another through the air space above the water level, whereby said plenums are adapted to individually supply combustion air each under its own positive pressure to the sections of the grate system respectively associated therewith at the same time that they serve as conduits for discharge into the trough water of the ash sifted through the grate system.

2. In an incinerator as defined in claim 1 wherein said air baffle means each comprises a downwardly inclined plate having its rear and opposite side edges respectively integrally secured to the top and bottom walls of said water, each said plates being loacted forwardly of one of said plenums.

3. In an incinerator as defined in claim 2 wherein each of said plates is provided with a curved portion adapted to be submerged in the tough-contained water whereby to block the passage of air through the air space in said water trough between successive ones of said plenums.

4. In an incinerator as defined in claim 1 wherein said water-retaining trough includes therein an endless drag conveyor mechanism having a series of longitudinally spaced material-dragging flights running along the bottom of said trough for the removal therefrom of the products of combustion discharged from the grate system through said plenums into said trough.

5. In an incinerator as defined in claim 4 wherein said conveyor mechanism is characterized by vertically spaced upper and lower runs of said drag flights, the upper run of flights being submerged in the water sufficiently for the flights thereof to engage and effect submergence in the water of those discharged products of combustion which float upon the surface of the water.

6. In an incinerator having a combustion chamber and agrate system therein for moving trash to be inciri erated longitudinally from the front to the rear end thereof through said combustion chamber, in combustion, a water-retaining trough extending lengthwise of and in vertically spaced relation below said grate sys tem, said trough having enclosing top, bottom and said walls and being filled with water to a substantially constant level spaced from the top wall of the trough, a plurality of open-ended plenums disposed in tandem relation lengthwise of said grate system with their top ends respectively immediately underlying successive sections of said grate system and their bottom ends respectively projecting through the top wall of said trough to points spaced above the level of water therein, an endless drag conveyor mechanism enclosed within said water trough, said conveyor mechanism having vertically spaced upper return and lower ash-removing runs of continuously moving longitudinally spaced drag flights, the lower working run of said conveyor mechanism being completely submerged in the trough water and disposed for running along the bottom of said trough for the removal therefrom of ash siftings discharged from the grate system through said plenums into said trough, the upper run of said drag flights being sufficiently submerged in the water to engage any particles of said ash siftings floating on the surface of said water, and means in said water trough to effect intermittent complete submergence of said upper run of flights successively at spaced points along their course of travel whereby the floating ash siftings discharged from the grate system are skimmed from the water surface and submerged into the water for gravitation to the bottom of the water trough.

7. In an incinerator as defined in claim 6 wherein said last-mentioned means are located each in such close association with each of said plenums that as the siftings are discharged from a given plenum into the water trough they are immediately engaged and submerged into the water by said upper run of flights to effect their gravitation through the water to the bottom of the water trough from whence they are removed by said lower working run of the drag flights.

8. In an incinerator as defined in claim 7 wherein said last-mentioned means consists of a plurality of plates secured to the top of the water trough at points spaced along the length of said trough in close proximity to the bottom discharge ends of said plenums, each said plate having a curved portion submerged in the water to successively depress the upper runs of the flights below the water level as said flights move past said plates. 

1. In an incinerator having a combustion chamber and a grate system therein for moving trash to be incinerated longitudinally from the front to the rear end thereof through said combustion chamber, in combination, a water-retaining trough extending lengthwise of and spaced vertically below said grate system, said trough having enclosing top, bottom and side walls and being filled with water to a substantially constant level spaced from the top wall of the trough, a plurality of open-ended plenums disposed in tandem relation lengthwise of said grate system with their top ends respectively immediately underlying successive sections of said grate system and their bottom ends respectively projecting through the top wall of said trough to points spaced above the level of the water therein, and baffle means secured to the top wall of said water trough and projecting into the water to block the passage of air from one plenum to another through the air space above the water level, whereby said plenums are adapted to individually supply combustion air each under its own positive pressure to the sections of the grate system respectively associated therewith at the same time that they serve as conduits for discharge into the trough water of the ash sifted through the grate system.
 2. In an incinerator as defined in claim 1 wherein said air baffle means each comprises a downwardly inclined plate having its rear and opposite side edges respectively integrally secured to the top and bottom walls of said water, each said plates being loacted forwardly of one of said plenums.
 3. In an incinerator as defined in claim 2 wherein each of said plates is provided with a curved portion adapted to be submerged in the tough-containEd water whereby to block the passage of air through the air space in said water trough between successive ones of said plenums.
 4. In an incinerator as defined in claim 1 wherein said water-retaining trough includes therein an endless drag conveyor mechanism having a series of longitudinally spaced material-dragging flights running along the bottom of said trough for the removal therefrom of the products of combustion discharged from the grate system through said plenums into said trough.
 5. In an incinerator as defined in claim 4 wherein said conveyor mechanism is characterized by vertically spaced upper and lower runs of said drag flights, the upper run of flights being submerged in the water sufficiently for the flights thereof to engage and effect submergence in the water of those discharged products of combustion which float upon the surface of the water.
 6. In an incinerator having a combustion chamber and a grate system therein for moving trash to be incinerated longitudinally from the front to the rear end thereof through said combustion chamber, in combustion, a water-retaining trough extending lengthwise of and in vertically spaced relation below said grate system, said trough having enclosing top, bottom and said walls and being filled with water to a substantially constant level spaced from the top wall of the trough, a plurality of open-ended plenums disposed in tandem relation lengthwise of said grate system with their top ends respectively immediately underlying successive sections of said grate system and their bottom ends respectively projecting through the top wall of said trough to points spaced above the level of water therein, an endless drag conveyor mechanism enclosed within said water trough, said conveyor mechanism having vertically spaced upper return and lower ash-removing runs of continuously moving longitudinally spaced drag flights, the lower working run of said conveyor mechanism being completely submerged in the trough water and disposed for running along the bottom of said trough for the removal therefrom of ash siftings discharged from the grate system through said plenums into said trough, the upper run of said drag flights being sufficiently submerged in the water to engage any particles of said ash siftings floating on the surface of said water, and means in said water trough to effect intermittent complete submergence of said upper run of flights successively at spaced points along their course of travel whereby the floating ash siftings discharged from the grate system are skimmed from the water surface and submerged into the water for gravitation to the bottom of the water trough.
 7. In an incinerator as defined in claim 6 wherein said last-mentioned means are located each in such close association with each of said plenums that as the siftings are discharged from a given plenum into the water trough they are immediately engaged and submerged into the water by said upper run of flights to effect their gravitation through the water to the bottom of the water trough from whence they are removed by said lower working run of the drag flights.
 8. In an incinerator as defined in claim 7 wherein said last-mentioned means consists of a plurality of plates secured to the top of the water trough at points spaced along the length of said trough in close proximity to the bottom discharge ends of said plenums, each said plate having a curved portion submerged in the water to successively depress the upper runs of the flights below the water level as said flights move past said plates. 